Carbon film and carbon film structure

Abstract

The present invention provides a carbon film that is remarkably excellent in current voltage (IV) characteristics. This is achieved by way of a carbon film structure, two or more carbon film assembly units 12 are formed on a substrate 10 . The carbon film assembly units 12 comprise: a stem-like carbon film 14 which is made into a film in the shape of a long and thin needle; and a branch-like carbon film cluster 16 which is made into a film so as to surround the stem-like carbon film 14 from the halfway to the lower part of this stem-like carbon film 14 . The stem-like carbon film 14 has the shape of a long and thin needle having a configuration which has a spiral streak-like step part 18 towards the distal end at the circumference face of a near tip and in which the radius becomes small as going to the distal end.

What is claimed is: 
     
       1. A carbon film characterized by graphene sheet multilayer overlaps, having an internal hollow, and a radius provided with an acicular shape becoming smaller towards a tip end, whereon a striated stepped portion of the film is formed spirally around the outer circumference of a peripheral face of the graphene sheet continuing toward the tip structure and sheet shape, wall shape, and pointed carbon films are formed at the striated stepped portion. 
     
     
       2. The carbon film according to  claim 1  wherein the striated stepped portion extending from a level part is a pointed carbon film unit having an internal hollow where two or more graphene sheet layers overlap, and become spirally piled up in a stage, are constituted towards a tip section, and is formed spirally on a boundary of each of many pointed carbon film units. 
     
     
       3. The carbon film according to  claim 2  wherein sheet shape, wall shape, and pointed carbon films are formed at the striated stepped portion. 
     
     
       4. A carbon film structure having two or more carbon film units where a carbon film unit is comprised of branch carbon film and stem carbon film, the branch carbon film is formed on substrate and the stem carbon film grows from the branch carbon film, and the stem carbon film is characterized by graphene sheet multilayer overlaps, having an internal hollow, and a radius provided with an acicular shape becoming smaller towards a tip end, whereon a striated stepped portion of the film is formed spirally around the outer circumference of with peripheral face of the graphene sheets continuing toward the tip structure, and a sheet shape, wall shape or needle shape carbon film is formed at the striated step portion. 
     
     
       5. The carbon film structure according to  claim 4  wherein the branched carbon film has the striated stepped portion following a circumference of a peripheral face towards the tip concerned. 
     
     
       6. The carbon film structure according to  claim 4  wherein a circumference of a peripheral face near a tip is turned at the tip concerned, and the striated stepped portion becomes spiral. 
     
     
       7. The carbon film according to  claim 6  wherein the striated stepped portion forms an internally hollow acicular carbon film unit of two or more layers of overlapped graphene sheets, and becomes spirally piled up in a stage, and are constituted towards a tip, and is formed spirally on a boundary of each of acicular carbon film units.